Your mom has no right to your child and is really crossing a line IMO. You need to realize she's not going to help at this point, and you need to withdraw--at least until you have a therapist that can help you figure out how to deal with her. Do not discuss your health with her anymore, just shut her out.

If you have friends that are more supportive and can utilize other resources like babysitting or cleaning help to lessen your load, GREAT. Worst case scenario, if you do separate eventually, you need to have things in place in order to be able to cope "on your own" with her. --And no judge will take her from you due to a disability, but you'll need to prove you have resources in place to manage.

I went out of pocket several thousand dollars for therapy instead of waiting for my insurance because I knew it was urgent at that point. Pre CRPS, I utilized free marriage counseling sessions with a few different ministers prior to my eventual divorce--my ex said he would participate but didn't. There are always options...

We can all empathize that you don't want to deal with CRPS--your husband and mother don't either apparently. The only thing worse then having CRPS short term, is having it long term. Your best chance of remission is having more intensive medical care right now, and for that to happen you need more support in order to care for your daughter. If it's not going to be from them, it has to come from somewhere else.